Supersonic training device



Aug. 15, 1950 P. ROSENBERG 2,518,938

suPERsomp TRAINING DEVICE Filed 001:. 19. 1945 2 Sheet's-Shget 1 FIG!H62 ,.4

FIG?) IN VEN TOR. PAU L ROSENBERG QM/QM 977411..

ATTORNEY Aug 5, 1950 P. ROSENBERG 2,518,938

SUPERSONIC TRAINING DEVICE Fild Oct. 19, 1945 Z'Sheet S-Sheet 2 TO RADIOOBJECT LOCATING SYSTEM V .INVENTOR. PAUL ROSENBERG.

BY W777- ATJ'ORNEY system were in an aircraft flying over the repre-Patented Aug. 15 1950 SUPERSONIC TRAINING DEVICE Paul Rosenberg,Brookline, Mass, assignor, by mesne assignments, to the United States ofAmerica as represented by the Secretary of War.

Application ctober19, 1945, Serial No. 623,412

This invention relates to relief maps and more particularly a supersonictrainer map in which portions of the map representing selectedgeographical areas are removable and replaceable.

In the copending application of Raymond L. Garman and Paul RosenbergSerial No. 623,409, filed Oct. 19, 194.5, now abandoned, there isdisclosed and claimed a map that will reflect supersonic energy to adegree proportional to the degree of reflection of electromagneticenergy from corresponding areas of the earths surface. This map is foruse in supersonic trainers that simulate the operation of radio objectlocating systems. One type of supersonic trainer consists of a radioobject locating system in which the transmitter and antenna are replacedwith a supersonic crystal transducer. The crystal transducer is adaptedto transmit a pulse of supersonic compressional wave energy upon receiptof a video pulse signal from the radio object locating system. Thecrystal transducer will also supply a video pulse signal to the radioobject locating system whenever an echo of the original transmittedpulse strikes the crystal of the transducer.

The transducer is suspended by means of suitable movable arms or tracksin a liquid filled tank. The size of this tank may vary but, by way ofexample only, it may be four by six feet in horizontal dimension and oneand onehalf feet in vertical dimension. Water is a satisfactory liquidto use in the tank.

The position of the transducer in the liquid ma be controlled manuallyor by means of suitable servo systems to simulate to scale the flight ofan aircraft. A reflector or map is placed in the bottom of the tank tocause the pulses of energy transmitted by the transducer to be partiallyreflected along their path of propagation so that the echoes of thesetransmitted pulses return to the transducer. The upper surface of thereflector is treated so that the supersonic echoes from various areas ofthe reflector simulate the reflection of electromagnetic energ fromcorresponding areas on the earths surface.-

When the trainer is in operation the operator of the radio objectlocating system sees on his viewing screen a constantly changingradarpic- .ture that accurately simulates the radar picture that wouldbe seen if the radio object locating sented area.

Certain types of radio object locating systems have been designed forprecise bombing and navigational work and these systems have sulfi-.cient accuracy to distinguish details'in acity.

1 Claim. (01. s '.4)

Such details include streets, buildings, rivers, parks and so forth. f

If the operators are to be trained to recognize fromran indicator screenvarious prominent landmarks in a city, the trainer map must containthese landmarks. I

It is an object of this invention, therefore, to provide a simplenovel'apparatus for constructing cities on a supersonic trainer map.

It is a further object of this'invention to provide apparatus foraltering a map iflandmarks or details of the earth's surface are changeddue to bombing or other reasons. For a better understanding of theinvention together with other and further objects thereof reference ishad to the following description taken in connection with theaccompanying drawing in which:

Fig. 1 is a schematic view of a portion ofthe earths surface;

Fig. 2 is a view of a sheet of material employed in making a supersonicmap;

Fig. 3 is a sectional view of the sheet of Fig. 2 taken along the line3-3;

Fig. 4 is a plan view of the part of the map representing a city;

Fig. 5 is a side elevation of the portion of the map shown in Fig. 4;

Fig. 6 is a second sectional view taken along the line 33 with the partof the map shown in Figs. 4 and 5 in place; and

Figure '7 is a diagrammatic representation of a supersonic traineremploying a map of the type shown in Figures 1 to 6.

Referring now to Fig. 1 there is shown a portion of the surface of theearth containing "a city l0. Rivers l2 are also shown but no otherdetails are shown sincethe invention does not involve the representationof terrain features in the area surrounding the city. a

In Figs. 2 and 3 there is illustrated a sheet of material commonly knownas safety glass in which an opening M has been made in the glass sheetl6. No openings have been made in the plastic sheet I8 or the secondglass sheet 20 which also form a part of the sheet of safety glass, Theopening I4 in sheet 10 is most easilymade by sandblasting the glass andthe opening should be approximately the size of area representing city[ll of Fig. 1. A supersonic map of the area surrounding city In may beconstructed .on..the exposed face of sheet [6 in the manner provided inthe above mentioned copending application or 'by any other similarmeans. The maps described in this copending application are constructedby roughening selected areas on the surface of a smooth sheet of glassuntil these selected areas reflect the energy in an incident beam ofsupersonic energy back along the path of the beam to a degreeproportional to intensity of the radar echo received from the portionsof the earths surface represented by these selected areas.

A small sheet 222 :of plastic (or 79171181 :material illustratedin Figs.4'and 5 is cut to fit the 'opening [4 in sheet [6, Fig. 3. The detailsof city 19 including streets 24 and blocks of buildings as are laid outto scale on sheet 22 ,usingrthesame method that is employed inconstructing a large supersonic map. The details "of ithestreets 24 andbuildings 26 appear in Figure 5= as thenneven surface 28 on the uppersurface o'fqalastic sheet 22. One convenient materialithatimayzbemsedconstructing cities is known by the commercial name of Scotchlite. Thismaterial consists'ofsheet=of'this materiahmay be fastened-tmsheet 22 andin areas that give little return--such as roads, parks, -etc., tne glass:beads m'ay be re- *moved I to reduce reflection.

After the detailsof the city havebeen completed sheet 22 is placed in'opening t'd in :the s'manner' -shown in Fig.6. sheet Q-Tmaybeqaer-*maQnently fastened in place or it may be fastened inplace so thatitmay'be rem'ove'd -so tthat :changes in the 'details of city H3 =-maybe rhade-fromtime to time. 'Thislatter methodof *fastening is--'desirable where the landmarks -of ra 'city'are apt tochange due toaddition Or destruction of structures or buildings.

*Someof the advantages ofthis methpd o'f=representing cities on a mapare: cne the fine-"121e- ?tails of the city maybe-constructed-under'fav- :orable working conditions-duetmthe smalbsizedsheet on which the map-of thecity'is constructed; .two, a new insert maybe -made-when the situai-tion demands it; *third, it is a relativelysimple matter to change inserts in themaprandfourth, *thedetails-ofthe'city may be constructed so-that they are flush with or even slightlybel'ew the "surface ofsheet 1 6 andthusavoid'sha'dows'in the *fieldpattern of the trainer thatmight result if .the map of the citywas"place'don-the-surfaceef -sheetl'fi;

*While the-"foregoing discussion has been l imited to a sheet of safetyglass having'an'cpening sandiblasted "therein, the invention *is by :nomeans "limited to theuse of this'material or to theuse iof'thismethodfor forming an opening. Solid glass, solidplastic, laminated plastic orany m'ateria lthat will causespecular reflectionof-a beam ,of supersonicenergy may be 'used ior 'th'e map 'ibase'and' the recess for *themitymay -beformed numeral 3| in Figure '7. As mentioned above the liquid 32in tank 39 may be water. A crystal transducer 34 schematicallyillustrated in the form of its electromagnetic equivalent, a smallparaboloid, is suspended beneath the surface of the liquid by means ofswing arm 36 and support 38. An electrical connection 40 to trans-:dueer P34 provides means for rconnecting the itransducer 34 toamodifiedwadio object-locating system. (Not shown.) In Fig. '7,connection 40 iis shown as terminating on support 38 but it is -.t0-' be11ndersto od that the circuit is completed to transducer'flby any meanswell known in the cart.

Dashedline 42 in Figure '7 represents the path of transmitted-supersonicenergy radiated from rtransducertsand. dashed line 44 represents the Vpath of the echo reflected from the surface of rec by drilling, etching,routing or any other 'means well known to the shop worker.

'-It=can be seen that more than-one city :may

be represented 'on .a mapif desired and :also :that ,5

map"'-3l. A portion of this reflected energy is received by transducer34 in the form of an echo signal.

In Figure 17 the (beam is fs'hown as hein'g 7:18- -flected-from aniareainclosedzwithina rectangle 58. YPectanglefl 6: represents aninsertdfithe' gtype .shown iniFiguresA and 5:of :the: drawing. It is .to %-be.understood, of :course, a that the supersonic -beam maylbe: directedatvother rparts of the :map 3 I by changing the "position ='o'ftransducer The-operation o'f the l'trainer 5 shown 'inFigm'e' I wvillndt 'be describediin detail.asince a brief ex- :pl-anation of its:operation thas' been given above and trainers-of this :general type arewell known 'inthesart. It is suflicient to stateithat a's tran's- :ducer:34 is moved -over :the surface 'of *map 31 theindication' appearing onthe indica'tondf 'the radio: obj ez'zt-lo catingvsystem associated withthis trainer is: ail-accurate representation of indication .that wouldappear on 'the indicator if the syflem waslocated'in1anaaireraft flyingover -area .of :the earths surface represented' 'by the rmap. alt =is tobe understood, o'f:course, that a'pzplicants novel map is not limited touse in 'the -partic1ilar lztype oi trainer descri'bed rather itadaptable for 'use :inall trainers operating on similar principles.

Therefore,'wliile there has been described what is at present consideredthe preferred embodiment of the invention, itwi1l be obviousto -'thoseskilled in the art-that various-changes andmodi- =Tications may bemade-therein withoutdeparting from the invention.

What isclaimed is:

A simulated airborne radar training device -'comprising a liquid filledtank, a map-like -re- =fiector' below the liquidsuria'celevel 2 insaid-tank, said reflector representing a "selected portion cf "theearths surfacaa transducer-below the liquid surfa'ce' levl in said tank,said-transducer being "laterally movable above said reflector, andadapted to=simulate the movement'of airborne radar, means for exciting'said "transducer to transmit supersonic energy for reflection from saidreflectonsaid reflector formed with-a'tleast one opening, the uppersurface ofsaid-reflebtor surrounding said opening being non-uniformlyrough such that the reflection of electromagnetic energy from said surface to said transducer "represents "to scale the degree of-deflectioriof electromagnetic energy from said selec'tedportion-of the earthssurface represented by the reflector, a removable reflector insertwithin saiid operiing and flush with said upper surface, said insert:representing 4 a particular geographical area and "havingmon-urii'forml-y roug'h surfaces such that ztank given inhezreierenee.ithe reflection ofsupersonic energyiirom said-suk face to saidtransducer represents to scale the degree of reflection ofelectromagnetic energy from said geographical area, and means responsiveto reception of reflected supersonic energy by said transducer.

PAUL ROSENBERG.

REFERENCES CITED The following references are of record in the file ofthis patent:

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